A secreted serine-threonine kinase determines virulence in the eukaryotic pathogen Toxoplasma gondii.

Toxoplasma gondii strains differ dramatically in virulence despite being genetically very similar. Genetic mapping revealed two closely adjacent quantitative trait loci on parasite chromosome VIIa that control the extreme virulence of the type I lineage. Positional cloning identified the candidate virulence gene ROP18, a highly polymorphic serine-threonine kinase that was secreted into the host cell during parasite invasion. Transfection of the virulent ROP18 allele into a nonpathogenic type III strain increased growth and enhanced mortality by 4 to 5 logs. These attributes of ROP18 required kinase activity, which revealed that secretion of effectors is a major component of parasite virulence.

Integrated graphical analysis of protein sequence features predicted from sequence composition.

Several protein sequence analysis algorithms are based on properties of amino acid composition and repetitiveness. These include methods for prediction of secondary structure elements, coiled-coils, transmembrane segments or signal peptides, and for assignment of low-complexity, nonglobular, or intrinsically unstructured regions. The quality of such analyses can be greatly enhanced by graphical software tools that present predicted sequence features together in context and allow judgment to be focused simultaneously on several different types of supporting information. For these purposes, we describe the SFINX package, which allows many different sets of segmental or continuous-curve sequence feature data, generated by individual external programs, to be viewed in combination alongside a sequence dot-plot or a multiple alignment of database matches. The implementation is currently based on extensions to the graphical viewers Dotter and Blixem and scripts that convert data from external programs to a simple generic data definition format called SFS. We describe applications in which dot-plots and flanking database matches provide valuable contextual information for analyses based on compositional and repetitive sequence features. The system is also useful for comparing results from algorithms run with a range of parameters to determine appropriate values for defaults or cutoffs for large-scale genomic analyses.

Surveys of complementary and alternative medicine: part III. Use of alternative and complementary therapies for HIV/AIDS.

A series of 16 independent studies of the human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) community and their use of alternative and complementary therapies over the past 10 years helps document the changes that have occurred. The earlier studies are characterized by political activism, lack of confidence in conventional therapies, and widespread use of alternative pharmacological therapies and unapproved drug use. The improvement of conventional treatment since the mid-1990s has been accompanied by a greater emphasis on complementary therapies used in conjunction with conventional drug therapy. Mind-body or psycho-spiritual therapies that help the patient cope with stress and adjust to life-threatening illness are the most popular.

Surveys of complementary and alternative medicine: Part II. Use of alternative and complementary cancer therapies.

The second part of this series on surveys of complementary and alternative medicine (CAM) in the United States provides a "point-of-information" summary of the studies on patients with cancer and their use of CAM therapies. Surveys of patients with cancer were the precursors of the recent wave of studies on CAM prevalence and use. Three tables summarize the findings from a total of 18 surveys categorized by Childhood Cancer, Adult Cancer, and Breast Cancer studies.

Evidence for different mechanisms of chloroquine resistance in 2 Plasmodium species that cause human malaria.

Chloroquine (CQ)-resistant Plasmodium vivax malaria was first reported 12 years ago, nearly 30 years after the recognition of CQ-resistant P. falciparum. Loss of CQ efficacy now poses a severe problem for the prevention and treatment of both diseases. Mutations in a digestive vacuole protein encoded by a 13-exon gene, pfcrt, were shown recently to have a central role in the CQ resistance (CQR) of P. falciparum. Whether mutations in pfcrt orthologues of other Plasmodium species are involved in CQR remains an open question. This report describes pfcrt homologues from P. vivax, P. knowlesi, P. berghei, and Dictyostelium discoideum. Synteny between the P. falciparum and P. vivax genes is demonstrated. However, a survey of patient isolates and monkey-adapted lines has shown no association between in vivo CQR and codon mutations in the P. vivax gene. This is evidence that the molecular events underlying P. vivax CQR differ from those in P. falciparum.

Surveys of complementary and alternative medicine: part I. General trends and demographic groups.

Data from the surveys of the Harvard team, led by David Eisenberg, M.D., are frequently used as a summary first paragraph introduction to the status of complementary and alternative medicine (CAM) in the United States. However, there is now a substantial body of literature on various facets of CAM use. Six national surveys to date are briefly discussed and summarized in a table. Some surveys have been conducted at a regional level. Three are summarized but there are too few data yet to draw any conclusions. Eighteen more exploratory surveys of specific subpopulations are presented to help draw a clearer picture of income, ethnic, and age groups. The search strategy is provided. The changing terminology in the field, the development of the CAM survey, and some common shortcomings are also addressed.

Surveys of complementary and alternative medicine: part IV. Use of alternative and complementary therapies for rheumatologic and other diseases.

This fourth review in the series covers eight recent U.S. surveys on complementary and alternative medicine (CAM) use by patients with rheumatologic and other autoimmune conditions, and summarizes seven studies of other disease categories. Regarding the previous reviews, the acronym CAM is used unless it is possible to refine the concepts. This reflects the problem that most survey questionnaires do not differentiate between adjunct or complementary therapies and alternative approaches to treatment.

Mutations in the P. falciparum digestive vacuole transmembrane protein PfCRT and evidence for their role in chloroquine resistance.

The determinant of verapamil-reversible chloroquine resistance (CQR) in a Plasmodium falciparum genetic cross maps to a 36 kb segment of chromosome 7. This segment harbors a 13-exon gene, pfcrt, having point mutations that associate completely with CQR in parasite lines from Asia, Africa, and South America. These data, transfection results, and selection of a CQR line harboring a novel K761 mutation point to a central role for the PfCRT protein in CQR. This transmembrane protein localizes to the parasite digestive vacuole (DV), the site of CQ action, where increased compartment acidification associates with PfCRT point mutations. Mutations in PfCRT may result in altered chloroquine flux or reduced drug binding to hematin through an effect on DV pH.

Use of complementary medicine by adult patients participating in HIV/AIDS clinical trials.

OBJECTIVE: To identify and characterize patterns of use of complementary and alternative (CAM) therapies by human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients participating in clinical trials in a research setting. DESIGN: A descriptive survey using a nonrandom sample of 100 patients was conducted over 17 months, using a 99-item interview schedule adapted from a previous study. SETTING: National Institutes of Health (NIH) Warren G. Magnuson Clinical Center. SUBJECTS: Patients diagnosed with HIV/AIDS, participating in clinical research protocols at the National Institute of Allergy and Infectious Diseases and the National Cancer institute (NCI) at the NIH. RESULTS: Ninety-one percent (91%) had used at least one CAM therapy, as defined by a 1993 study by Eisenberg et al., sometime in their lives. Postdiagnosis, 84% used at least one CAM therapy with an average of just fewer than 5. The increase in frequency of use from 64% prediagnosis was significant (P2 = 0.019). Therapies that became significantly more popular postdiagnosis were, imagery (P2 = 0.00012), high-dose vitamins, (P2 = 0.000019), weight gain (p2 = 0.000244), massage (p2 = 0.00091), relaxation (p2 = 0.0033), herbals (p2 = 0.013), spiritual (p2 = 0.024), and acupuncture (p2 = 0.035). They were primarily used for HIV/AIDS-related problems: dermatological, nausea, depression, insomnia, and weakness. There was a high level of agreement that benefits of CAM use were: feeling better, 51 (98.1%), increased coping, 52 (100%), feeling in control, 44 (88.5%), and enhanced treatment outcome, 49 (94.2%) with 32 (61%) stating CAM was as, or more effective than conventional treatment. Fifty-three percent (53%) were specifically asked by physicians whether they were using adjunct therapies. CONCLUSIONS: Subjects used a variety of CAM therapies to cope with their diseases and rigors of treatment and clinical trials. Further research is needed to identify CAM therapies that may be used as adjunct treatments during clinical trials.

Use of herbal therapies by adults seen in an ambulatory care research setting: an exploratory survey.

OBJECTIVE: To identify and characterize patterns of use of herbal products among patients participating in selected research clinics. DESIGN: Survey of three National Institutes of Health (NIH) ambulatory care research clinics. SUBJECTS: Convenience sample of 490 adult patients (168 male, 322 female) attending rheumatology, liver, and endocrinology/metabolic research clinics. RESULTS: Of the patients surveyed, 16.7%: (n = 82) reported using herbs. There were no significant sociodemographic differences between herb and nonherb users. Indications for herb use differed among the disease groups; patients in the endocrine and rheumatology clinics were taking herbs predominantly for "energy" or "wellness"; those attending the liver clinic tended to use herbal therapies as treatment for their disease. Mean and median monthly expenditure for herbal products was $30 and $10, respectively. There was a significant positive correlation between number of herbs used and use of other dietary supplements (p < 0.0001). CONCLUSIONS: One in six patients in ambulatory clinical research settings may be taking herbal products in addition to prescribed treatment. This figure is lower than in the general population, possibly because the patients may stop using herbs when participating in a research project. Although empirical evidence on the beneficial or adverse effects of herb therapy alone or in combination with drug therapies is limited, clinical researchers should be aware of the potential for confounding clinical trial results.